Resolves https://github.com/spring-projects/spring-integration/issues/3526
`FailoverClientConnectionFactory`
The logic to detect we had iterated over all factories and including
the one from which the previous connection was established was incorrect,
causing an infite loop until one of the factory connections was successful.
Change the logic to detect we have reset the iterator and the current failure
is from the same factory as the one from which the previous connection was
established.
**cherry-pick to 5.4.x, 5.3.x**
* Add diagnostics.
* Fix race in test.
* More race fixes and diagnostics.
* Remove diagnostics.
7abbe30c81